This thesis argues that the 1848 revolutions played a key role in the development of the political thought of the Young Hegelians, Arnold Ruge, Bruno Bauer, Moses Hess and Karl Marx. They all developed revolutionary ideas in the 1840s and hoped for revolutionary events as those that unfolded in 1848, but their theories failed to predict the outcome of the revolution. In the empirical analysis this thesis clearly demonstrates that the Young Hegelians under study changed their theoretical outlooks as a direct result of the 1848 revolutions. It is argued that the mechanism for this change is intellectual disillusionment. The idea is that these intellectuals became disillusioned with the theories they had developed in the 1840s because they experienced the 1848 as an intellectual failure.